I need to compile my patch into a Max5 application to run on a Windows 7 machine. I don't have Win7 myself and I am wondering if I could just as well use XP for it. Would there be any difference in the dlls and resulting app?
Although Andrew's response is correct as far as it goes, depending on what you're doing you may find behavior differences (technically referred to as "gotchas":-) on different flavors of Windows.
For instance, I had an app that was writing temp files for audio input. Worked fine on XP. Vista and 7 didn't like the location used in certain circumstances, however, at which point the app needed some restructuring to find a new home for those temps.